1. Field of the Invention
Motorcycle brakes, more specifically a motorcycle brake for the rear wheel of a motorcycle in which a pulley driving the rear wheel has, integral therewith, a rotor, more specifically a retrofit brake and pulley assembly for fitting to the hub of a rear wheel of a motorcycle.
2. Background of the Invention
Motorcycles are enjoying a resurgence in popularity, especially Harley Davidson, America's oldest motorcycle and manufacturer of the most popular cruiser motorcycle in the world.
Motorcycles have a frame, an engine, wheels, control systems and a means for braking or slowing the motorcycle. For many years, braking in motorcycles as in cars, was done with drum brakes. Drum brakes have an outer drum which rotates with the wheel of the vehicle. Inside the outer drum are brake shoes actuated on levers to expand outwardly against the inner surface of the rotating drum. This worked well for many years. However, in the early fifties automobiles were getting faster, tires and suspension were improving, and, therefore drum brakes were generating far more heat than before. With the generation of heat in the drum, "brake fade" would sometimes occurred. First Jaguar and then other automobile manufacturer adopted disc brakes which had been used earlier on aircraft. The disc brake attaches a disc shaped rotor to the wheel and uses a caliper in which hydraulically actuated pistons act against brake pads which are, in turn, urged against the spinning rotor. Since, except for the area of the rotor directly adjacent the caliper body, the disc is free to spin through the air, more affective cooling results than is available from drum brakes.
Motorcycles followed automobiles and eventually adopted disc brakes. Disc brakes were first used for the front wheel and then for the rear wheel. In motorcycles and cars, during braking, most of the stopping force is generated on the front wheel or wheels and therefore it is the front wheel or wheels on which the disc brake first appeared. However, it has become fairly common practice in the motorcycle industry today to provide the rear wheel with a disc or rotor. Indeed, the popular Harley Davidson is manufactured with a rear wheel mounted disc on the (driver's) right hand side. The rear Harley-Davidson wheel is driven by a toothed pulley attached to the left side of the hub which is driven by a toothed rubber belt which, in turn, is driven by a drive sprocket emerging from the engine cases on the left side of the motorcycle engine (driver's left). However, for various reasons, many of the motorcycle riders, including Harley Davidson enthusiasts, desire the right side of the motorcycle to look "clean"--that is, uncluttered. Utility therefore, lies in the removal of the disc from the right side of the hub of the motorcycle to the left (pulley) side. Further, utility lies in providing an intragal pulley and rotor unit wherein one can remove the rotor from the right side of the motorcycle and incorporate it into a pulley on the left side of the motorcycle.
Utility also lies in providing a unitized pulley and rotor system which can bolt directly onto a preexisting bolt hole pattern of the hub of the rear wheel of a motorcycle. By doing so, the user is released from the difficult and potentially dangerous task of drilling holes into the hub of a motorcycle to mount a rotor thereto. Further, utility lies in providing a rotor which is attachable to a pulley-rather than directly to the hub and in a pulley which is machined with bolt holes matching the preexisting bolt holes of the hub of the motorcycle. Therefore, in summary, utility lies in providing an integral pulley and rotor unit in which the rotor attaches to the pulley and the pulley to the hub. Utility also lies in providing such a feature where the pulley and rotor unit can be bolted onto the existing bolt hole pattern of an OEM hub.
Additional utility lies in providing a rotor mounting or fastening system which allows some "play" or movement left and right and up and down of the rotor with respect to the pulley to which is attached. Such a feature will help minimize heat transfer from the rotor to the pulley, such heat generation on the pulley being deleterious to the belt.
Further utility lies in providing such a unit with teeth, the teeth for engaging a belt driven by the motor, which teeth are hard anodized to reduce wear.
Additional utility lies in providing a pulley and rotor unit which is dimensioned to help promote the flow of air past the rotor, thereby increasing the effectiveness of the cooling of the rotor.
Applicant further finds utility in providing a ductile iron rotor for attachment to an aluminum pulley, with a third metal fastening the rotor to the pulley to minimize the transfer of heat.
Applicant finds yet further utility in providing a caliper with brake pads for engagement with the rotor, the caliper including means to locate the caliper body adjacent the inner perimeter of the rotor.
Set forth above are some of the utilitarian features found in Applicant's unique brake and pulley assembly, others will be apparent from a review of the specifications and drawings set forth herein.